Decorative sheet

ABSTRACT

An object of the present invention is to provide a decorative sheet which can be adhered on a surface of an article having a three-dimensional curved surface, even when the operation is conducted in a place of operation at such a temperature as 40 to 60° C., and which does not use vinyl chloride resin. The present invention discloses a decorative sheet having a decorative layer, a protective layer disposed on a surface of the decorative layer, and an adhesive layer formed on the other surface of the decorative layer, wherein the decorative layer comprises a thermoplastic resin, the protective layer is composed of a resin composition comprising an amorphous polyester resin, and both the decorative layer and the protective layer have a glass transition temperature of 20 to 60° C.

FIELD OF THE INVENTION

The present invention relates to a decorative sheet, and particularly toa decorative sheet that is adhered to a surface of an article having athree-dimensional curved surface, such as an outside or inside surfaceof a building and a vending machine in order to decorate the surface ofthe article.

BACKGROUND OF THE INVENTION

A decorative sheet is a thermoplastic sheet having a decorative image onone surface and an adhesive layer on the other surface and is used forproviding decorative images on a surface of an article having athree-dimensional curved surface, such as an outside or inside surfaceof a building and a vending machine. The decorative sheet is generallyadhered on a surface of an article by the following two methods:

(1) A decorative sheet is heated in a place for operation to a giventemperature, generally 40 to 60° C. and is adhered on an article underpressuring when the decorative sheet is kept in the given temperature.

(2) A decorative sheet is adhered on an article by a molding method,such as vacuum molding under heating and the like.

Typically, the decorative sheet is made of such a material that eitherone of the methods or both are applicable. A decorative sheet that hasbeen used for this purpose is usually composed of a vinyl chloride resinas thermoplastic resin sheet. The vinyl chloride resin has good heatmoldability and good surface properties, such as wear resistance,chemical resistance and the like. The vinyl chloride resin, however, hasrecently been avoided and desirously replaced with another resin thatcan be disposed of without harm or one that can be recycled.

In order to comply with the above requirement, Japanese KokaiPublication No. 48014/1996 proposes a decorative sheet formed from apolyolefin resin, such as polyethylene or polypropylene as thermoplasticresin sheet. Japanese Kokai Publication No. 2000-94596 also proposes adecorative sheet having a protective layer formed from polyester resinthereon.

However, the polyolefin resin disclosed in Japanese Kokai Publication48014/1996 is crystalline and therefore has a softening temperature toohigh (more than 100° C.) to conduct a heat adhesion using such atemperature that a handy heating apparatus, such as a dryer can be usedin a place for operation.

In addition, the decorative sheet suggested in Japanese KokaiPublication 2000-94596 is designed for the operation (2) mentioned aboveand therefore is difficult to conduct adhesion in a place of operationby using a handy heating apparatus, such as a dryer. The polyester resinsuggested in the this publication has a glass transition temperature of60 to 85° C. and therefore is not adhered at a temperature less than 60°C. which is generally a heatable temperature by a heating apparatus,such as dryer.

SUMMARY OF THE INVENTION

Briefly, a decorative sheet is provided that can be adhered onto asurface of an article having a three-dimensional curved surface, evenwhen the operation is conducted in a place of operation at such atemperature as 40 to 60° C. Advantageously, the decorative sheet of thepresent invention does not use vinyl chloride resin.

The present invention provides, a decorative sheet that comprises adecorative layer, a protective layer disposed on a surface of thedecorative layer, and an adhesive layer formed on the other surface ofthe decorative layer,

wherein the decorative layer comprises a thermoplastic resin, theprotective layer is composed of a resin composition comprising anamorphous polyester resin, and

both the decorative layer and the protective layer have a glasstransition temperature of 20 to 60° C.

Because the glass transition temperature (Tg) of the decorative layerand the protective layer is adjusted to not more than 60° C., thedecorative sheet can easily be adhered even when it is heated in situfor operation at a temperature of generally 40 to 60° C. This improvesthe in-place processing and film application. In this context, the term“Tg (glass transition point or glass transition temperature)” is definedto be a peak temperature determined by a differential scanningcalorimeter.

Generally, if the Tg of the decorative or protective layer is less than20° C., the decorative sheet has a poorer mar resistance or poorer wearresistance. However, such decorative sheet, that is, one with a Tg ofless than 20C, can be used for short-term projects or applicationslasting generally not longer than about six months. This decorativesheet is not recommended for longer term applications.

The decorative sheet has an elongation preferably of not less than 30%at 40° C. and of less than 400% at 60° C., when the elongation isdetermined after the decorative sheet is left for 10 minutes at a giventemperature under a tension of 9.8 N/25 mm. Generally, shapecompatibility to a curved surface is somewhat decreased when theelongation at 40° C. is less than 30%. If the elongation at 60° C. ismore than 400%, the decorative sheet may be deformed or even broken whenthe decorative sheet is shaped on a curved surface at a relatively hightemperature immediately after heating. It is more preferred that thedecorative sheet has an elongation of not less than 33% at 40° C. and anelongation of less than 350% at 60° C.

It is also preferred that the decorative sheet has an elongation of 100%to 350%, when the elongation is determined after the decorative sheet isleft for 10 minutes at 50° C. under a tension of 9.8 N/25 mm. Generally,shape compatibility to a curved surface is somewhat decreased when theelongation at 50° C. is less than 100%. If the elongation at 50° C. ismore than 350%, the decorative sheet may be deformed or even broken whenthe decorative sheet is shaped on a curved surface at a relatively hightemperature immediately after heating. It is more preferred that thedecorative sheet has an elongation of 150 to 300% at 50° C. Theelongation is determined by placing a test sample at a given temperaturecondition, applying a tensile strength of 9.8 N/25 mm and keeping it for10 minutes, followed by determining an elongation.

It is preferred that the protective layer has a thickness larger thanthe decorative layer, effectively inhibiting breakage of the decorativesheet at a relatively high temperature while keeping high shapecompatibility. A thickness ratio (P/D) of the protective layer (P) tothe decorative layer (D) is generally within the range of 2 to 15,preferably within the range of 3 to 10. It is also preferred that theprotective layer has a thickness of 80 to 500 μm, preferably 120 to 450μm, more preferably 150 to 350 μm. If it is too thick, shapecompatibility to a curved surface is reduced when it is heated andcooled thereafter. If it is too thin, the decorative sheet is moresusceptible to breakage and, depending on hardness and resilience of thedecorative layer, the decorative sheet may be partially separated fromthe article to be decorated.

The decorative layer of the decorative sheet is different from theprotective layer, in physical properties and materials, generallybecause function and effect of each layer are different. Accordingly,interfacial delamination between the decorative layer and the protectivelayer may occur during the application process. It is thereforepreferred that a primer layer be inserted between the decorative layerand the protective layer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross sectional view of the decorative sheet ofthe present invention.

DETAILED DESCRIPTION OF THE INVENTION

Decorative Sheet

One example of the decorative sheet of the present invention, as shownin FIG. 1, is composed of a decorative layer (1), a protective layer (2)having a back layer (22), contacted on the surface (11) of thedecorative layer, and a adhesive layer (3) contacted on the back surface(12) of the decorative layer (1). The decorative layer (1) may be formedfrom a resin layer having a graphic printed thereon, a resin layercontaining colorant or a laminate containing such resin layer. In anembodiment illustrated in FIG. 1, a primer layer (4) is present betweenthe decorative layer (1) and the protective layer, for enhancingadhesion power, although primer layer (4) is an optional layer.

The adhesive layer (3) is formed from a coating containing an adhesivepolymer and a crosslinking agent, similar to a conventional adhesivesheet. On an adhesive surface of the adhesive layer, a release liner (5)is generally disposed. The liner can have small roughness on a releasesurface, which controls adhesive power by transferring the roughness tothe adhesive layer from the release layer. It is preferred that thesmall roughness would disappear by a plastic deformation of the adhesivelayer after finishing adhering, so that the distinguishness of thedecorative sheet would not be damaged.

Protective Layer

The protective layer is formed from an amorphous polyester resincomposition. The amorphous polyester resin has good heat extensionability that is advantageous for enhancing shape compatibility to curvedsurface in hand adhering operation of the decorative sheet. Theamorphous polyester resin has high transparency, less whitening whenextended and exhibits good solvent resistance.

Although it is preferred that the protective layer has hightransparency, it may be translucent or colored transparency forenhancing design properties of the decorative sheet. The protectivelayer generally has a light transmittance of not less than 65%,preferably not less than 70%. In the present specification, the “lighttransmittance” is determined by a measuring method of lighttransmittance according to JIS K 7105.

An elongation of the protective layer partially governs the elongationof the decorative sheet of the present invention. It is thereforepreferred that the protective layer has an elongation of not less than30% at 40° C. and of less than 400% at 60° C., when the elongation isdetermined after the decorative sheet is left for 10 minutes at a giventemperature under a tension of 9.8 N/25 mm. Generally, shapecompatibility to a curved surface is somewhat decreased when theelongation at 40° C. is less than 30%. If the elongation at 60° C. ismore than 400%, the decorative sheet may be deformed or even broken whenthe decorative sheet is shaped on a curved surface at a relatively hightemperature immediately after heating. It is more preferred that thedecorative sheet has an elongation of not less than 33% at 40° C. and anelongation of less than 350% at 60° C.

It is also preferred that the protective layer has an elongation of 100to 350%, when the elongation is determined after the decorative sheet isleft for 10 minutes at 50° C. under a tension of 9.8 N/25 mm. Generally,shape compatibility to a curved surface is somewhat decreased when theelongation at 50° C. is less than 100%. If the elongation at 50° C. ismore than 350%, the decorative sheet may be deformed or even broken whenthe decorative sheet is shaped on a curved surface at a relatively hightemperature immediately after heating. It is more preferred that theprotective layer has an elongation of 150 to 300% at 50° C.

The protective layer may be subjected to techniques of embossing orcalendaring to enhance design properties, as long as it does notadversely affect on the technical effects of the present invention. Inthis context, the embossing gives some protrusions on the surface and acombination of the protrusions and the portions around the protrusioncreates three-dimensional designed appearance. The calendaring makes theprotective layer smooth to reduce surface roughness, which impartsspecular gloss appearance.

Polyester Resin Composition

The protective layer is formed from a resin composition that contains athermoplastic amorphous polyester resin, wherein the resin compositionhas a glass transition temperature of 20 to 60° C. and excellenttransparency.

The amorphous polyester resin composition may contain (i) a phthalatetype polyester resin, such as polyethylene terephthalate, polybutyleneterephthalate, polyethylene naphthalate and the like; and (ii) apolyether compound that is at least partially soluble with the phthalatetype polyester resin. In this combination, the phthalate type polyesterresin behaves as a thermoplastic resin and the polyether compoundbehaves as a plasticizer or softening agent. The combination has a largeelongation even at a relatively low temperature and exhibits goodtoughness even at relatively high temperature. The amorphous resincomposition provides shape compatibility to a curved surface when thedecorative sheet is adhered by hand at a temperature of 40 to 60° C.

The phthalate type polyester resin is a polyester that has in onemolecule both (a) a repeating unit derived from phthalic acid ornaphthalic acid, such as terephthalic acid, isophthalic acid ornaphthalic acid, and (b) a repeating unit derived from diol. Thepolyester can be prepared by reacting dicarboxylic acid (e.g. phthalicacid or phthalic anhydride) and diol, such as by condensationpolymerization.

The diols can be a mixture of (b-1) a linear aliphatic diol, such asethylene glycol, 1,4-butane diol, 1,6-hexane diol, caprolactone diol andthe like; and (b-2) an alicyclic diol, such as 1,4-cyclohexanemethandiol, cyclohexane diol and the like. The amorphous polyester canpreferably be prepared from the diol mixture as mentioned above. Theamorphous polyester resin can easily give shape compatibility to acurved surface when the decorative sheet is adhered by hand at atemperature of 40 to 60° C.

It is preferred for the amorphous polyester resin of the presentinvention that a weight ratio of diols i.e. (b-1):(b-2), is 10:60 to80:20.

The dicarboxylic acid or its derivative can be those other than phthalicacid. The amorphous polyester resin may preferably has a number averagemolecular weight of at least 10,000, more preferably of 15,000 to1,000,000.

The amorphous polyester resin is commercially available, includingEaster PETG polyester, available from Eastman Kodak Co. and the like.

The polyether compound can be an alkylene glycol type ether compoundwhich contains a repeating unit of alkylene glycol having 2 to 6 carbonatoms. The alkylene glycol type ether compound includes 1) apolyalkylene glycol diether obtained by alkyl-etherifying both end of apolyalkylene glycol (e.g. polyethylene glycol or tetramethylene glycol),or 2) a polyester ether having both alkylene glycol unit anddicarboxylic acid unit. The alkyl group for etherifying preferablyincludes a lower alkyl group (having not more than 3 carbon atoms), suchas methyl group, ethyl group and propyl group. Examples of dicarboxylicacids for the 2) are an aromatic dicarboxylic acid, such as terephthalicacid, isophthalic acid, phthalic acid, 2,6-nephthalene dicarboxylicacid, 1,5-naphthalene dicarboxylic acid and the like.

The polyalkylene glycol unit of the polyether compound can preferably bepolyethylene glycol unit, which shows a large elongation even at arelatively low temperature and has good toughness even at a relativelyhigh temperature.

The polyether compound generally has a number average molecular weightof 400 to 6,000, preferably 450 to 3,000, more preferably 500 to 3,000.Molecular weights more than 6,000 reduce an elongation of the resincomposition at a low temperature and those less than 400 reduce atoughness of the resin composition at a high temperature.

The polyether compound may generally have a melting point of 150 to 250°C., a melt viscosity of 500 to 30,000 poise when determined at a shearrate of 100 sec⁻¹ and a temperature of 250° C. Within the above range,the polyester resin composition can be formed into film by aconventional film-forming method, such as extruding method to easilyobtain polyester film used for the protective layer. The polyethercompound preferably has a Tg (peak temperature of tan δ) of −50 to 30°C., more preferably −40 to 25° C., most preferably −30 to 20° C.

The polyether compound can be commercially available under tradenames,such as Butycel, Butycenol, Kyowanol, and the like.

The polyester resin composition may contain another additive, inaddition to the essential components (i.e. thermoplastic polyester resinand polyether compound), as long as it does not damage the transparencyand heat extending ability of the present invention. The other additiveincludes colorant (e.g. dye, pigment etc.), plasticizer, softeningagent, surfactant, filler (including glass beads or ceramic beads),crosslinking agent, frame retardant, ultra-violet absorber, oxidationstabilizer, anti-fungus agent or the like. The additive may preferablycontain in an amount of not more than 20 parts by mass based on 100parts by mass of the essential components.

Decorative Layer

The decorative layer of the present invention may be either (1) a resinlayer containing colorant and thermoplastic resin, or (2) a resin layerand a printing layer or portion fixedly disposed on the resin layer. Theprinting step may be conducted by electrostatic printing, gravureprinting, silk printing, ink-jet printing and the like, and the resinlayer can be one that has high affinity with ink or toner for printing.The opposite surface of the decorative layer may have a primer layer toenhance adhesive power with the adhesive layer.

The decorative layer may be prepared by preparing a paint containingthermoplastic resin as main component and coating and solidifying(drying or curing) it. Coating can be conducted by a notch bar, a roundbar or the like. In addition, the decorative layer may be formed bymelt-extruding a material containing a film-forming polymer.

The thermoplastic resin for the decorative layer may includepolyurethane, acrylic resin, polyester, silicone resin, ionomer,ethylene-vinyl acetate copolymer or the like; or a mixture thereof. Forexample, a mixture of polymethyl methacrylate copolymer and ethyl-vinylacetate copolymer enhances both toughness and elongation with keepingbalance. The thermoplastic resin may preferably have a lighttransmittance of not less than 60%, more preferably not less than 70%.

The decorative layer may further contain an additive, in addition to thethermoplastic resin and optional colorant. The additive may includemetal gloss particle, plasticizer, softening agent, surfactant, filler(including glass beads or ceramic beads), crosslinking agent, frameretardant, ultra-violet absorber, oxidation stabilizer, anti-fungusagent or the like. The decorative layer preferably contain a plasticizerto control elongation within a desired range. The additive maypreferably contain in an amount of not more than 30 parts by mass basedon 100 parts by mass of the thermoplastic resin.

The decorative layer may preferably have a desired elongation for easyoperation of adhering. The decorative layer may also has a thickness of10 to 400 μm, preferably 15 to 200 μm.

Adhesive Layer

The adhesive layer generally contains adhesive polymer. The adhesivepolymer may include acrylic polymer, silicone polymer, α-polyolefinpolymer, rubber polymer (e.g. synthetic rubber, such as SBS etc. ornatural rubber), polyurethane polymer or the like. The adhesive polymermay be used alone or in combination. The adhesive polymer may beprepared by polymerizing a monomer mixture containing suitable monomers.Polymerization can be conducted by a conventional method, such assolution polymerization, bulk polymerization, emulsion polymerization orthe like.

The acrylic adhesive polymer may generally be prepared by polymerizing amonomer mixture of (A) an alkyl acrylate having 4 to 8 carbon atoms and(B) an (meth)acrylic acid monomer having a carboxylic group in amolecule. Another monomer to be copolymerized with the above twomonomers, such as (meth)acrylic monomer and a vinyl-group containingmonomer can also be used.

Examples of the monomer (A) are n-butyl acrylate, iso-butyl acrylate,isooctyl acrylate, 2-ethylhexyl acrylate, and the like. Examples of themonomer (B) are (meth)acrylic acid. Examples of the other monomers arephenoxyethyl acrylate, phenoxypropyl acrylate, 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxymethyl(meth)acrylate, hydroxy-3-phenoxypropyl acrylate, glycidyl(meth)acrylate, acryloyl benzophenone and the like.

The adhesive polymer may generally be crosslinked. The crosslinking maybe conducted by reacting a crosslinking agent and polymer. Thecrosslinking agent is not specifically limited, but includes isocyanatecompound, epoxy compound, bis-amide compound and the like. Thecrosslinking agent may be contained in an amount of 0.1 to 5 parts bymass, based on 100 parts by mass of the adhesive polymer.

The adhesive layer may contain resilient microbaloon or crystallinepolymer, as long as they do not adversely affect on the technicaleffects of the present invention. The resin which has re-adheringability may be used. The adhesive layer may have a thickness of 5 to 200μm, preferably 10 to 100 μm, as long as the purpose of the presentinvention can be attained.

Primer Layer

The primer layer may be fixedly disposed either on a surface of thedecorative layer or on a backside of the protective layer, and thenadhered to another layer to be adhered. The primer layer may be formedfrom a primer polymer which is selected from a polymer having affinitywith both the decorative layer and the protective layer. The primerpolymer may be vinyl chloride-vinyl acetate copolymer, urethaneelastomer or aminoethyled polymer, in case where the decorative layercontains acrylic resin as thermoplastic resin. The presence of theprimer layer may increase adhesion between the protective layer and thedecorative layer.

The aminoethyled polymer is a polymer into which a primary amine group(—NH₂) is introduced by a method using ethyleneimine. It is generallyreferred “aminoethyling” that a primary amine group is introduced byring-opening ethylene imine and adding. Accordingly, in the presentspecification, a polymer into which a primary amine group is introducedby the above method is referred as an aminoethyled polymer oraminoethyled resin. In addition, the urethane elastomer can be anelastomer formed from a polyurethane obtained by polymerizing a startingmaterial containing polyol and diisocyanate.

The primer layer may have a thickness of 0.1 to 30 μm, preferably 0.5 to10 μm. Also, the primer layer may have a light transmittance of not lessthan 80%, preferably not less than 85%.

The primer layer may be formed by coating a solution containing theprimer polymer on the decorative layer (or protective layer, andsolidifying by curing or drying. Coating may be conducted by a coater,such as a gravure coater, a bar coater, a naf coater, a roll coater, adie coater or the like.

Method of Forming the Decorative Sheet

The polyester resin composition for the protective layer is formed intoa polyester film by a conventional film-forming method. The film-formingmethod of the polyester resin may include T-die method, inflationmethod, calendar method, cast method or the like.

The polyester film used for the protective layer may be prepared asfollow. A amorphous copolyester resin is mixed with a polyether compoundin a given amount ratio and, if necessary, dried at 100 to 150° C. forseveral hours to 10 hours to obtain a starting mixture. The startingmixture is put into an extruder and extruded at a desired temperature(generally 180 to 280° C.) and a desired die temperature (generally 180to 260° C.) and then quenched by a casting roller to form a polyesterfilm. The polyester film is a non-extended film, but if necessary, itmay be monoaxially or biaxially oriented.

A mixing ratio of the amorphous copolyester resin and the polyethercompound may generally be within the range of 70:30 to 99:1, preferablywithin the range of 80:20 to 97:3, more preferably 85:15 to 95:5. If theamorphous copolyester resin is too much, the resin composition reducesthe elongation at a low temperature. It the polyether is too much, theresin composition does not have enough toughness at a high temperature.

The resulting polyester film as the protective layer is contacted withthe surface of the decorative layer which is separately prepared and puttogether. The decorative layer is prepared as mentioned above and theprimer layer is disposed thereon.

Lastly, an adhesive layer is fixedly disposed on the backside of thedecorative layer to form a decorative sheet of the present invention.The adhesive layer may be formed either by preparing a paint containingadhesive polymer and then coating directly on the backside of thedecorative layer, followed by drying, or by coating the paint on arelease liner and contacting it with the backside of the decorativelayer. A support layer may be inserted between the decorative layer andthe adhesive layer. The support may be stretchable polymer film, porousfilm (e.g. non-woven fabric or woven fabric), metal film containingmesh, or the like.

EXAMPLES

The present invention will be explained with reference to the followingExamples.

Example

In this Example, a decorative sheet as shown in FIG. 1 was prepared. Aprotective layer was prepared as follow. An amorphous polyester resinand a polyether compound were put into an extruder and extruded into anamorphous polyester film having a thickness of 200 μm, which was used asprotective layer.

The amorphous polyester resin was prepared by polymerizing a monomermixture of (a) terephthalic acid, (b-1) ethylene glycol, and (b-2)1,4-butane diol in an amount ratio of (a):(b-1):(b-2) being 66:16:18(mass ratio). The polyether compound was a polyethylene glycol dimethylether having an average molecular weight of about 430. The amorphouspolyester resin was contained in the resin composition in an amount of92% by mass.

The protective layer obtained above had a Tg of 36° C. The Tg of thisExample was determined using a differential scanning calorimeter DSCavailable from Perkin Elmer Co. by raising temperature at a rate of 10°C./min within a temperature range of −50° C. to 160° C. Its Tg wasspecified from a peak temperature of the chart obtained above.

Next, a decorative layer was prepared using a acrylic resin (methylmethacrylate copolymer having Tg of 50° C.) as thermoplastic resin asfollow. Hundred parts by mass of the thermoplastic resin was mixed with20 parts by mass of an adipic acid-polyester as plasticizer and apigment as colorant to form a film material. The colorant was dispersedin the plasticizer before adding the resin mixture. The film materialwas formed into a polymer film by an extruding method to use it as adecorative layer. The decorative layer had a thickness of 30 μm toensure sufficient opacifying power.

The decorative layer was coated to form a primer layer formed from vinylchloride-vinyl acetate copolymer by gravure coating to form thedecorative layer. The decorative layer with the primer layer and theprotective layer were laminated and heat pressured by a heat roller toform a decorative sheet of the present invention.

Comparative Example

A decorative sheet was prepared as generally described in Example, withthe exception that both decorative layer and protective layer wereprepared from crystalline polyolefin film.

Evaluation of Decorative Sheet

(1) Elongation

The decorative sheet was cut into a sample of 25 mm width ×100 mmlengthen. The sample was oriented along the direction of lengthen by anorientation machine using 1 Kg weight (9.8 N/25 mm) and left at a giventemperature for 10 minutes, followed by determining a value ofelongation. The results are shown in Table 1.

TABLE 1 Elongation(%) Comparative Temperature Example Example  23° C. 0 0 (Ambient temperature)  30° C. 3  0  40° C. 35  0  50° C. 225  0  60°C. 320  0  70° C.  —*  1  80° C. —  1  90° C. —  1 100° C. —  2 110° C.—  3 120° C. —  5 130° C. —  9 140° C. — 30 150° C. — >200*  *film broke

The decorative sheets of Comparative Example did not show elongation atless than 130° C., because the resin for the protective layer anddecorative layer had high crystallinity. On the other hand, thedecorative sheets of Example was suitably softened at temperatures of 40to 60° C. which is a temperature of adhering operation. This shows thatthe decorative sheet can be extended by a hand.

Operability in Place of Operation

The decorative sheet of Example was heated and softened by a drier toadhere on a three-dimensional curved surface. For comparison, a Dinoc®commercially available for a decorative sheet using a vinyl chlorideprotective layer was used and the same operation was conducted.Operability in place of operation was compared with each other. As theresult, it was found that the operability in place of operation did nothave any difference therebetween.

1. A decorative sheet comprising a decorative layer, a protective layerdisposed on a surface of the decorative layer, and an adhesive layerformed on the other surface of the decorative layer, wherein thedecorative layer comprises a thermoplastic resin, the protective layeris composed of a resin composition comprising an amorphous polyesterresin, both the decorative layer and the protective layer have a glasstransition temperature of 20 to 60° C., and the decorative sheet has anelongation of not less than 30% at 40° C. and of less than 400% at 60°C., the elongation being determined after the decorative sheet is leftfor 10 minutes at a given temperature under a tension of 9.8 N/25 mm. 2.The decorative sheet according to claim 1, wherein the decorative sheethas an elongation of 100 to 350%, the elongation being determined afterthe decorative sheet is left for 10 minutes at 50° C. under a tension of9.8 N/25 mm.
 3. The decorative sheet according to claim 1, wherein theprotective layer has a thickness larger than the decorative layer. 4.The decorative sheet according to claim 3, wherein the protective layerhas a thickness of 80 to 500 μm.
 5. The decorative sheet according toclaim 1, wherein between the decorative layer and the protective layeris present a primer layer for enhancing an adhesion of the layers. 6.The decorative sheet according to claim 1, wherein the decorative layeris adhered to a surface of an article having a three-dimensional curvedsurface.
 7. The decorative sheet according to claim 6, wherein thearticle comprises an outside or inside surface of a building or avending machine.
 8. The decorative sheet according to claim 1, whereinthe decorative layer further comprises a colorant.
 9. The decorativesheet according to claim 1, wherein the decorative layer furthercomprises a printing layer thereon.
 10. The decorative sheet accordingto claim 1, further comprising a release liner on the adhesive layer.11. The decorative sheet according to claim 1, wherein the decorativesheet does not contain vinyl chloride resin.
 12. The decorative sheetaccording to claim 1, wherein the protective layer has a lighttransmittance of not less than 65%.
 13. The decorative sheet accordingto claim 1, wherein the protective layer has an embossed surface. 14.The decorative sheet according to claim 1, wherein the amorphouspolyester resin comprises (a) a first polyester having both (i) arepeating unit derived from phthalic acid or naphthalic acid, and (ii) arepeating unit derived from one or more diols; and (b) a polyethercompound that is at least partially soluble in the first polyester. 15.The decorative sheet according to claim 14, wherein the one or morediols comprise (i) a linear aliphatic diol selected from the groupconsisting of ethylene glycol, 1,4-butane diol, 1,6-hexane diol, andcaprolactone diol; and (ii) an alicyclic diol selected from the groupconsisting of 1,4-cyclohexane methandiol and cyclohexane diol.
 16. Adecorative sheet comprising a decorative layer, a protective layerdisposed on a surface of the decorative layer, and an adhesive layerformed on the other surface of the decorative layer, wherein thedecorative layer comprises a thermoplastic resin, the protective layeris composed of a resin composition comprising an amorphous polyesterresin, and both the decorative layer and the protective layer have aglass transition temperature of 20 to 60° C.; wherein the decorativesheet does not contain vinyl chloride resin, and the amorphous polyesterresin comprises (a) a first polyester having both (i) a repeating unitderived from phthalic acid or naphthalic acid, and (ii) a repeating unitderived from one or more diols; and (b) a polyether compound that is atleast partially soluble in the first polyester.
 17. The decorative sheetaccording to claim 16, wherein the one or more diols comprise (i) alinear aliphatic diol selected from the group consisting of ethyleneglycol, 1,4-butane diol, 1,6-hexane diol, and caprolactone diol; and(ii) an alicyclic diol selected from the group consisting of1,4-cyclohexane methandiol and cyclohexane diol.
 18. The decorativesheet according to claim 16, wherein the decorative layer is adhered toa surface of an article.
 19. A decorative sheet comprising a decorativelayer, a protective layer disposed on a surface of the decorative layer,and an adhesive layer formed on the other surface of the decorativelayer, and a release liner on the adhesive layer, wherein the decorativelayer comprises a thermoplastic resin, the protective layer is composedof a resin composition comprising an amorphous polyester resin, both thedecorative layer and the protective layer have a glass transitiontemperature of 20 to 60° C., and the decorative sheet has an elongationof not less than 30% at 40° C. and of less than 400% at 60° C., theelongation being determined after the decorative sheet is left for 10minutes at a given temperature under a tension of 9.8 N/25 mm.
 20. Thedecorative sheet according to claim 19, wherein the amorphous polyesterresin comprises (a) a first polyester having both (i) a repeating unitderived from phthalic acid or naphtbalic acid, and (ii) a repeating unitderived from one or more dials; and (b) a polyether compound that is atleast partially soluble in the first polyester.